1. Field of the Invention
The present invention relates to a storage system configured by a management computer and a storage subsystem, and a method for controlling such a storage system and, more specifically, to a method for activating a storage device to which a power saving function is applied.
2. Description of the Related Art
1. Storage Area Network
A network connecting one or more computers and one or more storage subsystems called a storage area network (SAN). Such a connection over the SAN between the computer (s) and the storage subsystem (s) is established when a plurality of computers provide one function by working together, or when one or more computers are allowed to share one large-capacity storage subsystem, for example. With such a connection established over the SAN between the computer(s) and the storage subsystem (s), there are advantages of being able to easily add, remove, and replace the storage resources and computer resources as appropriate so that the resulting system can offer excellent scalability.
2. Disk Array Device
The storage subsystem (s) for connection to the SAN are popularly a disk array device(s). The disk array device carries therein a large number of storage devices typified by hard disk and flash memory, for example.
The disk array device manages a plurality of storage devices as a group with the RAID (Redundant Array of Independent Disks) technology. This group of storage devices is referred to as RAID group. The RAID group forms one or more logical storage areas. Any computer connected to the SAN executes a data input/output process with respect to such storage areas. When the computer performs data recording to the storage areas, the disk array device records redundant data of one or two of the storage devices configuring the RAID group. This recording of redundant data leads to advantages of, when any one of the storage devices are broken down, being able to restore the data from the remaining storage devices in the RAID group.
3. Backup Technology
With a well-known backup technology, in a disk array device, two types of logical storage areas are set, i.e., one serves as a copy source, and the other serves as a copy destination. Alternatively, any of a plurality of disk array devices may be set to serve as a primary logical storage area(s) and the remaining disk array devices may be each set to serve as a secondary logical storage area. After such setting, to be ready for possible data loss in the primary logical storage area, data reading is performed therefrom, and thus read data is written into the secondary logical storage area(s).
4. Power Supply Control Technology Based on Service Plan
With a previous power supply control technology, in a storage system including a plurality of storage subsystems, the storage subsystems are each provided with a power supply control program for control of components and a main power supply circuit therein. Based on an operation plan of services utilizing storage areas in the storage devices, a power supply control command program provided in a management computer moves the storage areas to be utilized for the services to any other storage subsystems, and issues a command for controlling the components and the main power supply circuit in each of the storage subsystems. An example includes Patent Document 1 (JP-A-2006-187993).